Shirt collar



FIG. 1 is an isometric view of a shirt collar, shown in use;

FIG. 2 is an isometric view thereof;

FIG. 3 is a front elevation view thereof;

FIG. 4 is a rear elevation view thereof;

FIG. 5 is a left elevation view thereof; the right elevation view being a mirror image thereof;

FIG. 6 is a top elevation view thereof; and,

FIG. 7 is a bottom elevation view thereof.

The broken lines shown in the drawings illustrate portions of the shirt collar that form no part of the claimed design. 

CLAIM The ornamental design for a shirt collar, as shown and described. 